Materials Data on CeAl8O16 by Materials Project
CeAl8O16 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Ce is bonded to twelve O atoms to form CeO12 cuboctahedra that share corners with four equivalent CeO12 cuboctahedra, faces with four equivalent CeO12 cuboctahedra, and faces with eight AlO6 octahedra. There are a spread of Ce–O bond distances ranging from 2.49–2.57 Å. There are eight inequivalent Al sites. In the first Al site, Al is bonded in a square co-planar geometry to four O atoms. There are a spread of Al–O bond distances ranging from 1.73–1.84 Å. In the second Al site, Al is bonded in a linear geometry to two O atoms. There is one shorter (1.61 Å) and one longer (1.63 Å) Al–O bond length. In the third Al site, Al is bonded to six O atoms to form distorted AlO6 octahedra that share corners with five AlO6 octahedra and faces with four equivalent CeO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–21°. There are a spread of Al–O bond distances ranging from 1.82–2.06 Å. In the fourth Al site, Al is bonded in a linear geometry to two O atoms. There is one shorter (1.62 Å) and one longer (1.63 Å) Al–O bond length. In the fifth Al site, Al is bonded in a square co-planar geometry to four O atoms. There are a spread of Al–O bond distances ranging from 1.75–1.84 Å. In the sixth Al site, Al is bonded to six O atoms to form distorted AlO6 octahedra that share corners with five AlO6 octahedra and faces with four equivalent CeO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–21°. There are a spread of Al–O bond distances ranging from 1.82–2.06 Å. In the seventh Al site, Al is bonded in a square co-planar geometry to four O atoms. There is two shorter (1.76 Å) and two longer (1.80 Å) Al–O bond length. In the eighth Al site, Al is bonded in a square co-planar geometry to four O atoms. There is two shorter (1.76 Å) and two longer (1.80 Å) Al–O bond length. There are sixteen inequivalent O sites. In the first O site, O is bonded in a linear geometry to two Al atoms. In the second O site, O is bonded to four equivalent Ce and two Al atoms to form a mixture of edge and corner-sharing OCe4Al2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the third O site, O is bonded in a linear geometry to two Al atoms. In the fourth O site, O is bonded in a linear geometry to two Al atoms. In the fifth O site, O is bonded in a linear geometry to two Al atoms. In the sixth O site, O is bonded in a linear geometry to two Al atoms. In the seventh O site, O is bonded in a 2-coordinate geometry to two equivalent Ce and two equivalent Al atoms. In the eighth O site, O is bonded in a 2-coordinate geometry to two equivalent Ce and two equivalent Al atoms. In the ninth O site, O is bonded in a linear geometry to two equivalent Al atoms. In the tenth O site, O is bonded in a linear geometry to two equivalent Al atoms. In the eleventh O site, O is bonded in a linear geometry to two equivalent Al atoms. In the twelfth O site, O is bonded in a linear geometry to two equivalent Al atoms. In the thirteenth O site, O is bonded in a linear geometry to two Al atoms. In the fourteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ce and two equivalent Al atoms. In the fifteenth O site, O is bonded in a linear geometry to two Al atoms. In the sixteenth O site, O is bonded in a distorted rectangular see-saw-like geometry to two equivalent Ce and two equivalent Al atoms.